Decoupling Photochemical and Photothermal Effects Using Molecular Motors Enables Fast, Intelligent, and Life-Like Motions in Soft Materials

The development of synthetic smart materials that perform on-demand tasks in complex environments, while triggered noninvasively, is a major goal to develop the next generation of soft robotics. However, fast and complex locomotion with high spatial-temporal precision using external stimuli controlling shape in such systems remains a major challenge. Here, we describe a light-responsive soft material based on liquid crystal polymer networks (LCPNs) with variable stiffness comprising highly efficient light-driven molecular rotary motors and dye molecules. This system selectively responds to light of specific wavelengths, enabling highly programmable and complex motions, such as jumping, rotating, and climbing. The rapid response of molecular motor triggered by UV-light (photochemical effect) and the heat generated by dye upon red-light irradiation (photothermal effect), can be decoupled and orthogonally controlled, due to unique features of the molecular motor. Our study shows how cooperativity and amplification of molecular motion can lead to the rapid actuation of synthetic materials, which offers novel molecular tools and materials engineering perspectives for the development of intelligent soft robotics.